Archive for the ‘teaching’ Category

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Logitech Cordless 2.4 GHz Presenter

Thursday, February 26th, 2009

A while ago I blogged about buying “the clicker”, aka the Targus Wireless presenter tool. If you do not know what it is, let me explain. You know how sometimes when people are doing a Power Point presentation they walk away from their computer and just have that little gizmo in their hand that let’s them advance slides remotely? Yeah, it’s that thing. Mine was a chepo, plastic thing with a few rudimentary buttons and a built in red laser pointer.

All in all, it served me well for over a year. Lately though I started having problems with it. It would just stop working for me in the middle of the class forcing me to use the keyboard to advance slides. Students were slowly getting accustomed to the 5 minutes of extra time at the start of the lecture as I tinkered with the damn contraption. Sometimes I was able to coerce it to work. Other times, I had to stop messing with it and start the class.

Eventually I figured out what was wrong with it. The spring that holds the single AAA battery in place lost some of it’s “springiness”. It became less “springy”. It “de-springified” itself, so to say. As a result and the battery gained unexpected freedom of choice. It could choose to stay in place or slide slightly out of position. The battery cover was not designed support it, and it did not hold it in place. Instead it gave it just enough space to slip off the connector, but not enough space to rattle around. So you wouldn’t know the battery was lose, until you popped the cover up, and pushed it back in.

Any sudden movement had the potential of shaking the battery out of alignment again, forcing you to pop the cover again to restore power to the device. It’s actually very distracting when you are trying to teach something.

So I decided it is time for a new “clicker”. I also decided I’m not going to go for the cheapest thing available this time around. I believe that the Targus was pretty much the crappiest model available, and I’m actually amazed it lasted that long. It was sort of an experiment – I actually didn’t know I would use it so much. I ended up liking it, and now I consider the clicker/laser pointer combo to be an indispensable tool.

I believe that if you are going to be using something a lot, then it’s probably a good idea to invest a little bit of money into it. For example, I spend most of the hours in my day typing on a keyboard and using a mouse. I go to work, and I type and mouse around for about 8 hours. Then I go back home only to type and mouse around some more.

It is in my best interest to ensure that the keyboard and the mouse I use so much are of decent quality. That’s why I’m using the Sidewinder mouse and the Natural Ergonomic Keyboard 4000. Both are high end items that I paid premium for, but hey – it was worth it. You can save on other things, but these two items are essential tools that I use both for work an for play.

Same goes for the “clicker”. I teach once or twice a week, and I sometimes do get to present in front of people for other purposes. It is not an essential tool for my job, but it helps. So I picked the Logitech Cordless 2.4 GHz Presenter which was one of the higher end toys. I don’t think it’s top of the line, but it seemed like a good investment. Besides, I never really had a bad experience with Logitech products – their mice and keyboards are usually very dependable. So I was hoping they use the same quality control for their “clicker” things. Here is a picture for you:

logitech-cordless.jpg

Yes, it does look a little bit like an electric shaver/hair trimmer from afar. It’s smaller than that though. It is much smaller than that. Something that big would be impractical. Here is another picture, this time with someones hand so that you can see the scale of this thing:

logitech_presenter_hand.jpg

As you can see, it’s quite handy. It fits well in your hand, and is larger than the Targus model, which is actually a good thing. You can get a better grip on it, and the sleek elongated shape makes it easier to hold while you are pointing at things. The USB connector slides right into the unit which means I won’t loose it or forget it as easily. It always annoyed me that the Targus model did not provide this feature.

One of the very crucial things with these presentation tools is that they absolutely need to work out of the box. I need to be able to walk into a classroom, plug it in and go. Installing drivers is out of the question since the school machines are pretty tightly locked down. I’m happy to report that this model worked flawlessly under Windows XP. I haven’t tested it under Vista yet, but I assume it won’t be much different.

And yes, it has an LCD screen. Why would it have and LCD screen? Well, it’s a timer which is what really sold me on this model. You see, keeping track of time has always been an issue for me. When I do presentations, I’m in full screen mode which means I don’t see the clock on the screen. So if I need to check the time, I have to look at my watch… Which is my cellphone. Yeah, I actually don’t own any wrist mounted watches that work – the batteries run out in all of them, and I have been to lazy to go see a clock-master-repairman-guy to perform the sacred ritual of battery replacement.

Yeah, I did replace my watch batteries once or twice but half of the time the operation involved me putting dents and scratches into the back panel, loosing the rubber insulation parts and not sealing the thing properly. So I’d rather give the nicer, more expensive watches to a professional. But I’m kindoff scared – there is an off-chance that I do in fact have latent superpowers (something that I have always suspected) and the watch-guy may turn out to by Sylar and he will remove my brain or something.

Ok, that was a Heroes Season 1 reference if you haven’t caught it. I haven’t really watched the show since then – I will need to catch up one day. The first few episodes of season 2 failed to capture my attention. But I digress..

Back to presentations, and checking time. Looking at my cell phone is probably not the best time keeping solution. It’s hard to do it discretely. I would sometimes take it out, and put it on the desk for easy access, but most of the time I forget and leave it on my belt clip. So if I need to check the time, I have to reach for my belt, un-clip the phone and push a button so that the front LCD display lights up. The Logitech Presenter tool has a built in timer that you can set yourself. It’s actually very easy one-button set up. Each time you press the “timer” button you add 5 minutes to the counter and it starts counting down back to zero. At any time you can glance at the display to see how much time you have left. When the countdown reaches 5 minutes it will alert you with a slight vibration. It will do it again at the 2 minute mark to let you know it’s time to wrap up. The signal is inaudible when you hold it in your hand. It can also be a bit startling at first. I knew it was coming, but it sort of surprised me during my first lecture. You get used to it though, and it is a very helpful.

This particular “clicker” comes with a nice little protective case you can slide it into so that it doesn’t get too bumped up in your backpack. The button locations are pretty good, and the laser pointer is bright and… Pointy?

I only used it couple of times, but so far it has been performing flawlessly. I must say I’m happy with the purchase, and I recommend it to anyone searching for a good presentation tool. The timer is a life saver, and it is worth getting it fro that feature alone.

Posted in gadgets, hardware, teaching, technology | 7 Comments »

Write LOGO Code…

Tuesday, January 6th, 2009

As you may remember, this past semester I had my students do some very simple programming exercises in LOGO. The lab session could actually be considered a success since most of the students seemed to enjoy playing with the Tortue interpreter.

On the final exam I decided to include an extra credit question to see how many students have retained any understanding of that lab session. It asked the students to draw two squares of different color on the canvas and it was worth 10 points that would get added to the student’s total score. I wasn’t really looking for 100% correct solution – merely an attempt that would show some degree of understanding of the question.

Since the question was optional and also non-trivial, I expected many people to skip it. Surprisingly quite a few students answered it with a high degree of correctness. In fact, I was surprised that more people attempted to answer the LOGO question rather than a very similar optional question which asked them to write down the syntax for a HTML table. But perhaps it’s because the HTML exercise we did was right after the midterm, while the LOGO lab was 2 weeks before the final so it was still fresh in their memory.

Most of the answers were either correct, or close to be correct. Only one made me laugh out loud though. And it’s not because I’m an evil bastard and I laugh at students failure. It’s because it was a genuine attempt at humor. I decided to scan it in and share it with you:

lgogo_code2.JPG

Get it? I said “Write Tortue Logo code” and he did. Anyways, I found it amusing. I reminded me of the infamous find x problem that has been passed around on the Internets for ages now:

findx.JPG

Find x is so ancient it doesn’t even seem to have an original source. That is, I’m sure there is one but I have no clue what it could be because just about every blog, forum and image board has posted and re-posted it a hundred times over without any attribution. In fact, I have seen people claiming that this image is not actual genuine scan from a test, but just something that someone did as a joke. Perhaps, but the limited amount of teaching experience that I have tells me that it probably is genuine. Especially since now I have my own variation on the same theme.

The question is – was this a homage, or an original attempt at humor that just turned out to be derivative. Cause, as you probably know we have exhausted almost all original content left in the universe around the turn of the century (if not earlier) and almost everything that is being created now re-uses old themes, tropes and ideas. This is especially true for internet culture which thrives on memetics, repetition and self referential humor.

Posted in humor, teaching | 5 Comments »

Electronic Test Taking

Monday, January 5th, 2009

I’m a fan of technology. I believe that most things can be made better via automation, virtualization and all the other *-tions that introduce technology into equation. In most cases, if something is preceded by “electronic” or “online” it means better. There are exceptions of course. One exception is called shitty implementation and unfortunately happens roughly 70% of the time. It happens to every one – that’s why we have websites like The Daily WTF.

Then there are things that should not be automated, mechanized or put online. One of these things is test taking. I dislike taking electronic tests, and as a rule I avoid giving them. I simply think they do not work as well as most people think they do. Sure, they are easy to administer, easy to grade, and easy to generate and randomize. You can build a database of questions, rate them by challenge level, and randomly generate unique tests of equal difficulty ad infinitum. But I believe they are not entirely fair to the students who take them.

For one, students are trained to take paper based tests. In most schools and universities, nearly all exams are administered using traditional methods such as blue books, or Scantron sheets or simple printouts that students fill out by hand and turn in. When you ask them to take an online test, you are working against years of conditioning and test taking habits. They are faced with unfamiliar format, unfamiliar input methods and a new interface. In fact a lot of test taking engines introduce distracting or stressful features that may negatively impact final scores.

For example, some electronic tests like to display the test score, or notify the taker whether they got the question right or wrong immediately after they have submitted the answer. I believe this is a mistake as it may easily create a negative feedback loop. A student who gets many questions in a row wrong, gets progressively more and more stressed. Each wrong answer adds to the pressure to the point of panic where most of the concentration is lost.

Displaying a ticking clock, elapsed time, or time left for the test may have similar effect. Students often start to do a lot of random guessing when they notice they are behind the clock. This goes double for engines which require that questions are answered within some specific time limit. Especially if test penalizes you for leaving blank answers.

These distractions and negative feedback loops do not exist in paper based tests. Students have unlimited amount of time to work on each question, and can keep track of the elapsed time at their own measure. They also do not know whether or not they got a given question right or wrong so they do not have to think about their score until after the test. Naturally, over time they could learn to ignore these types of distracting feedback. But this takes practice, and requires a uniform interface. But as I mentioned above, most students do not get to take online exams very often and thus lack the familiarity with the medium.

Electronic tests require a different test taking strategy. For example, one of the fundamental test taking tips is to skip difficult questions and then get back to them at the end. This prevents you from getting stuck on a difficult problem, and loosing too much time. Good test takers will tackle problems in an increasing order of difficulty to maximize the number of correct questions. Is this possible with electronic tests?

It really depends on implementation. Some test engines do not provide this functionality. Others do it by looping the questions around. When you deplete the list of questions, it starts showing you your skipped questions. Unfortunately most implementations do not allow for the level or prioritization allowed by a paper based test.

Electronic tests also do not allow you to back-track and “fix” the previously answered question. Test takers are often discouraged from doing this, implying that their first instinct is usually correct. Of course one has to remember most tests are flawed in such way that one question may give hints for solving a previous one. I will give you an example. Let’s say a test taker is asked for a definition of a buzzword, given 4 choices. He eliminates two of them right off the bat but not knowing the definition he makes a guess. Later on, the buzzword comes up again in one of the answers and through elimination the test taker is able to extrapolate that the have answered the previous question wrong.

Some people may say this is irrelevant, because the test taker did not know the answer to begin with. But the ability to connect the two questions, and correct the answer shows that the test taker is good at logically reasoning out hard problems based on given information. It may also indicate deeper understanding of the subject at hand. This is more valuable than mere ability to regurgitate memorized material and should be rewarded.

Electronic tests hardly ever allow you to change an answer that was already given. In fact, test engines that immediately indicate success or failure to answer a question make this type of reasoning impossible.

Not to mention that the test takers attention span may be different depending on the medium. It has been shown by countless studies that people tend to get bored and distracted with electronic, online and on-screen media much faster than with paper based media. That’s why most Youtube videos are short. That’s why blog posts tend to be short, and digestible in one sitting. So using medium that is commonly associated with fast paced, short attention span, burst communication to administer a long, drawn out test is not the best idea. Because of this attention span dissonance, a lot of electronic tests tend to seem more draining and exhausting than they should be.

These are the reasons why I dislike taking, and/or giving tests using electronic medium. I prefer good old scantron technology which combines a paper based test with a machine assisted grading. You just need to make sure you bring #2 pencils for everyone.

Of course, if you ignore the attention span problem, it would be possible to design an electronic test that would aim to emulate paper based experience. Make it look like an actual test booklet with several questions per page. Each question would have an active area where the student would check or type in answers. The engine would allow the student to scroll up and down, and flip pages, answer questions in random order even read the whole test without answering any questions without penalty. It would also have to allow the student to go back and fix previous answers at any time. In fact, such an interface could be easily designed using the all-present Web 2.0 design style and philosophy. But I haven’t seen anything like that in use yet. Have you?

Besides, a multiple choice tests can be machine-graded whether they are administered online or not as long as you use Scantron or similar scannable test sheets. Essay questions on the other hand must be graded “by hand” regardless of the medium. Online versions remove the issues with deciphering illegible handwriting, but other than that offer the same grading experience. So why not give students the paper based tests they are used to. If for nothing else, just for the tactile experience.

Posted in school, teaching, technology | 8 Comments »

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